Collision detection is the determination of whether or not two or more entities make contact with each other during gameplay.

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Collision detection with non-rectangular images

I'm creating a game and I need to detect collisions between a character and some parts of the environment. Since my character's frames are taken from a sprite sheet with a transparent background, I'm ...
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How to detect collisions between bullet and alien

I am designing a game for Android using Surface View. When a bullet hits any point on an alien it should blow the alien up. I wrote some code to detect collisions, but my code only triggers when my ...
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Matrix loading problems with jbullet and lwjgl

The following code does not load the matrix correctly from jbullet. //box is a RigidBody Transform trans = new Transform(); trans = box.getMotionState().getWorldTransform(trans); float[] matrix = new ...
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How to determine collision direction between two rectangles?

I am trying to figure out how to determine the direction a collision occurs between two rectangles. One rectangle does not move. The other rectangle has a velocity in any direction. When a collision ...
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990 views

3D collision detection with meshes using only raycasting?

I'm building a game using WebGL and Three.js, and so far I have a terrain with a guy walking on it. I simply cast a ray downwards to know the terrain height. How can I do this for other 3D objects, ...
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How do I determine if one polygon completely contains another?

I have 2 polygons. I know the vertex coordinates of both polygons. What's the best way to check if one is completely inside the other? For example, the algorithm should only recognize the black ...
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Bounding volume hierarchy - linked nodes (linear model)

The scenario A chain of points: (Pi)i=0,N where Pi is linked to its direct neighbours (Pi-1 and Pi+1). The goal: perform efficient collision detection between any two, non-adjacent links: (PiPi+1) ...
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2answers
373 views

What kind of physics to choose for our arcade 3D MMO?

We're creating an action MMO using Three.js (WebGL) with an arcadish feel, and implementing physics for it has been a pain in the butt. Our game has a terrain where the character will walk on, and in ...
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Java - 2d Array Tile Map Collision

How would I go about making certain tiles in my array collide with my player? Like say I want every number 2 in the array to collide. I am reading my array from a txt file if that matters and I am ...
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Solving 2D Collision Detection Issues with Relative Velocities

Imagine you have a situation where two objects are moving parallel to one-another and are both within range to collide with a static wall, like this: => 20m/s => 40m/s +==========+ ...
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Platformer Starter Kit - Collision Issues

I'm having trouble with my game that is based off the XNA Platformer starter kit. My game uses smaller tiles (16x16) then the original (32x40) which I'm thinking may be having an effect on collision ...
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Interpolation gives the appearance of collisions

I'm implementing a simple 2D platformer with a constant speed update of the game logic, but with the rendering done as fast as the machine can handle. I interpolate positions between actual game ...
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Collision Detection Problems

So I'm making a 2D tile based game but I can't quite get the collisions working properly. I've taken the code from the Platformer Sample and implemented it into my game as seen below. One problem I'm ...
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Should my game handle collisions in the Player object?

I'm making a 2D platform game. Right now I'm just working on making a very generic Player class. I'm wondering if it would be more efficient/better practice to have an ActionListener within the Player ...
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1answer
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Collision representation in game overworlds

I'm implementing a 2D overworld where one can walk through an area that is not tile based. I was wondering the best way to implement collisions. In the past when I've done similar things, I've used ...
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770 views

Collision detection in multiplayer games

This a followup to my previous question: How to implement physics and AoE spells in an MMO game?. There, we concluded that all physics have to be done on the server, and that I should use cylinders ...
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Tile map collision is not working properly

I am having problems setting collision between my sprite and the tiles. I have only done the code for colision for moving upwards but some places on the map it moves up and some places it doesn't. ...
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Spritesheet per pixel collision XNA

So basically i'm using this: public bool IntersectPixels(Rectangle rectangleA, Color[] dataA,Rectangle rectangleB, Color[] dataB) { int top = Math.Max(rectangleA.Top, rectangleB.Top); ...
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a simple 2D rectangle collision algorithm that also determines which sides that the rectangles collide?

I initially tried out implementing rectangular intersection, which works well. However, when I have to apply the physics system, such as velocity, acceleration, and directional vectors, I would have ...
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2D Tile-based Collision Detection

I've been planning an indie game project for a while now. I'll summarise it for you so I can get right to the question. It's done entirely using the latest version of XNA through Visual Studio. ...
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Circle inside circle collision

In one of my projects I have a game area in the shape of a circle. Inside this circle another small circle is moving around. What I want to do is keep the small circle from moving outside the bigger ...
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1answer
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What Do I Pass for inputGeometryTransform Parameter of ID2D1Geometry::CompareWithGeometry?

I have a list of ID2D1Geometry objects and I'm trying to use CompareWithGeometry to detect collisions in Direct2D; unfortunately, I'm not getting the results I need. I suspect I am improperly using ...
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Swept AABB vs Line Segment 2D

I've really exhausted as much as Google has to give, I've spent a solid week googling every combination of words for an "AABBvsLine sweep", downloaded countless collision demos, dissected SAT ...
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Deactivate keyboard input on collision

I'm creating an online-canvas-game with a tank as player object. Now I have several structures in my canvas, that shouldn't be able to be overdriven by the tank... My solution is to detect the ...
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2answers
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How can I optimise collision checks for a large number of AI units?

Let's say I got 100 Orcs in my 3D world and they all aim to kill each other. That means for every 1 Orc I have to check for collision with the 99 others. That will give me 99^2 which is about 10,000! ...
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How do I prevent my platformer's character from clipping on wall tiles?

Currently, I have a platformer with tiles for terrain (graphics borrowed from Cave Story). The game is written from scratch using XNA, so I'm not using an existing engine or physics engine. The tile ...
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Do I need to roll my own polygon segmentation algorithm to automate Box2d body creation from a tile map?

Before re-inventing the wheel I figured I'd ask: I'm working on a tile-based 2d-maze level generator for cocos2d + box2d. The idea is: I'm using one of the well-known graph traversal algorithms to ...
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Sliding collision response

I have been reading plenty of tutorials about sliding collision responses yet I am not able to implement it properly in my project. What I want to do is make a puck slide along the rounded corner ...
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2answers
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Issue with removing sprites on collision

I'm trying to make a very simple collision detection procedure just for test purposes. The problem is with the send/receive information between functions I have these lines on the update method ...
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OpenGL : Suggestion on handling collision detection and vertex data?

I was thinking how to do collision detection in my OpenGL application and came to conclusion that I should keep two copies of my geometry data. 1)First copy : Only for OpenGL rendering purposes.This ...
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Snake game - collision detection causing new position of apple to be rendered multiple times

I have a collision method implemented through the use of slick2d. When ever the snake collides with the apple, it causes the apple to be rendered in multiple places before the snake moves further ...
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2answers
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Collision, then what?

I know how to check collision for example 2 spheres. But my question is how do I use the collsion response in a good way? How do I make my character unable to walk in to the Sphere? I've got to the ...
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Collision with tile corners/seams in 2D platformer

There seems to be a lot of somewhat related questions answered already, but none I read answered my exact problem. I have a 2D platformer whose world is made entirely out of tiles that are in a ...
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CCSprite x and y comparison

I have 2 CCSprites and I want to tell if their x and y are equal I tried this: if(sam.position.x == tom.position.x && sam.position.y == tom.position.y){ NSLog(@"Hooray!"); } Although I do ...
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When is it the right time to start teaching collision detection?

I and a friend of mine started a game development club in our school two months ago and everything is going well for now. We are following McKesson's tutorials which I find comprehensive and ...
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C# XNA 4.0 Rectangle Rotation Collision

I can easily rotate my sprite, but how could I rotate my rectangle for my collision (Thinking of using the Separating Axis Theorem, But I have no clue how to apply it) Help or Example would be ...
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4answers
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3D: How how handle like 500 NPC

I'm currently working on a 3D game. My game have like 10 NPC's and a really small world. But if I want to have a larger world with lots of NPC's? I think it's not a good idea to update and check ...
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How can I convert a 2D bitmap (Used for terrain) to a 2D polygon mesh for collision?

So I'm making an artillery type game, sort of similar to Worms with all the usual stuff like destructible terrain etc... and while I could use per-pixel collision that doesn't give me collision ...
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Sphere and AABB intersection

I'm looking for an algorithm that will determine if a sphere is in any way touching an AABB or contained within it. Profile results indicate that this specific use is taking up a large percentage of ...
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Collision detected on only the latest added tile

I'm making a 2D platformer and I'm using tiles as the ground. I have a Tile class and I'm loading the tiles with the help of a list in the main game class: public static List<Tile> tiles = new ...
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What has the most efficient intersection test against an AABB tree - OBB, Cylinder or Capsule?

I'm currently trying to find collisions in 3D between a tighter volume than an AABB and a tree of AABB volumes. I just need to know whether they are intersecting, no closest distance or collision ...
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2D AABB vs AABB Sweep : How to calculate hit normal?

I've implemented a 2D AABBvsAABB sweep cast into my game, however, I'm having difficulty calculating the hit normal of the sweep cast. I have the sweep direction, both a and b AABB positions and xy ...
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Where in code to for collision? In object class? Mainline code?

Making a simple game in Love 2D framework where if I click on an object then it disappears. Do I check to see if I've clicked the enemy inside a function in the enemy object? Or just in my main.lua? ...
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GameObject and Components

I am creating a relatively simple game engine in C++ and Qt. I am using Irrlicht for graphics, and as of now, I will not be using any physics or audio libraries. For time's sake, I am using ...
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2answers
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Collisions between moving ball and polygons

I know this is a very typical problem and that there area a lot of similar questions, but I have been looking for a while and I have not found anything that fits what I want. I am developing a 2D ...
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1answer
618 views

3D Collision help

I'm having difficulties with my project. I'm quite new in XNA. Anyway, I'm trying to make 3D game and I'm already stuck on one basic thing. I have terrain made from a heightmap, and an avatar model. I ...
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Reflect angle on pong clone [duplicate]

I'm working on collision detection for a pong clone. I've calculated the angle of incidence but I can't find any information on how to specular reflect the angle I found. The code for calculating the ...
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AS3 hittest with a tweening movieclip, what is the best way?

I'm making a simple game. The character is movable with the arrow keys. The enemies are moving around the screen with a (classic) tween. I want to detect collision between the character and the ...
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How can I do fast Triangle/Square vs Triangle collision detection?

I have a game world where the objects are in a grid based environment with the following restrictions. All of the triangles are 45-90-45 triangles that are unit length. They can only rotate 90°. The ...
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Collision Detection Efficiency

I've just written my first successful collision detection code, and it works great for a small scene of actors (player + 4-5 obstacles). However, I realize that since it checks every possible ...